Toothbrush



FIG. 1 is a front elevation view of a toothbrush of my new design;

FIG. 2 is a right side elevation view thereof, the left side elevation view being a mirror image of the right side elevation view shown in FIG. 2;

FIG. 3 is a back elevation view thereof; and,

FIG. 4 is a top plan view thereof.

The bottom of the toothbrush forms no part of the claimed design. 

The ornamental design for a toothbrush, as shown and described. 